Memory devices having data lines included in top and bottom conductive lines

ABSTRACT

Some embodiments include apparatuses and methods having a first set of conductive lines, a second set of conductive lines, and memory cells located in different levels of the apparatuses and arranged in memory cell strings. At least a portion of the first set of conductive lines is configured as a first set of data lines. At least a portion of the second set of conductive lines is configured as a second set of data lines. Each of the memory strings is coupled to a respective conductive line in the first set of conductive lines and a respective conductive line in the second set of conductive lines. Other embodiments including additional apparatuses and methods are described.

BACKGROUND

Memory devices, such as flash memory, are widely used in computers andmany electronic items. Such memory devices usually have numerous memorycells to store information. Some conventional memory devices may consumerelatively less power but they may have lower data throughput. Someother memory devices may have a relatively higher data throughput butthey may have higher power consumption. In some cases, designing amemory device with both improved data throughput and power consumptionmay pose a challenge.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a block diagram of an apparatus in the form of a memorydevice, according to an embodiment of the invention.

FIG. 2A shows a schematic diagram of a portion of a memory device havinga set of top data lines formed from a set of conductive lines andanother set of bottom data lines formed from another set of conductivelines, according to an embodiment of the invention.

FIG. 2B repeats specific portions including memory cell sets of thememory device of FIG. 2A, according to an embodiment of the invention.

FIG. 3 shows a schematic diagram of a portion of the memory device ofFIG. 2A including a sense circuit, according to an embodiment of theinvention.

FIG. 4 is a timing diagram for the signals of FIG. 3 during an exampleread operation, according to an embodiment of the invention.

FIG. 5A shows a side view of a portion of a structure of the memorydevice of FIG. 2A, according to an embodiment of the invention.

FIG. 5B shows a top view of the portion of the structure of the memorydevice of FIG. 5A, according to an embodiment of the invention.

FIG. 5C shows another side view of a portion of the structure of thememory device of FIG. 2A, according to an embodiment of the invention.

FIG. 6A shows a side view of a portion of a structure of the memorydevice having bottom data lines formed over a substrate, according to anembodiment of the invention.

FIG. 6B shows another side view of a portion of the structure of thememory device of FIG. 6A, according to an embodiment of the invention.

DETAILED DESCRIPTION

FIG. 1 shows a block diagram of an apparatus in the form of a memorydevice 100 having a memory array 101 with memory cells 102, according toan embodiment of the invention. Memory cells 102 can be arranged in rowsand columns along with lines 150 and lines 170. Lines 150 can carrysignals WL0 through WLm and can form part of access (e.g., word) linesof memory device 100. Lines 170 can carry signals BL0 through BLn andcan form part of array data lines (e.g., bit lines) of memory device100.

Memory device 100 may use lines 150 to access memory cells 102, andlines 170 to exchange information (e.g., provide signals) with memorycells 102. A row decoder 108 and a column decoder 109 decode addresssignals A0 through AX on lines 103 (e.g., address lines) to determinewhich memory cells 102 are to be accessed in a memory operation.

Memory device 100 can perform memory operations such as a read operationto read information from memory cells 102 and a write (e.g.,programming) operation to write (e.g., program) information into memorycells 102. Memory device 100 can also perform an erase operation toclear information from some or all of memory cells 102.

A memory control unit 118 controls memory operations of memory device100 based on control signals on lines 104. Examples of the controlsignals on lines 104 include one or more clock signals and other signalsto indicate which operation (e.g., read, programming, or eraseoperation) memory device 100 can perform.

Other devices external to memory device 100 (e.g., a memory accessdevice, such as a processor or a memory controller) can control thevalues of the control signals on lines 104. Specific values of acombination of the signals on lines 104 can produce a command (e.g.,read, programming, or erase command) that can cause memory device 100 toperform a corresponding memory operation (e.g., read, programming, orerase operation).

Memory device 100 can include a select circuit 120 that is configured toselectively couple lines 170 associated with memory cells 102 to sensecircuit 140 through lines 174 in a memory operation, such as a readoperation.

Sense circuit 140 is configured to determine the value of informationfrom memory cells 102 in a memory operation, such as a read operation,and provide the information in the form of signals to lines 175 (e.g.,data lines). Sense circuit 140 can also use the signals on lines 175 todetermine the value of information to be written (e.g., programmed) intomemory cells 102.

Memory device 100 can include an input/output (I/O) circuit 117 toexchange information between memory array 101 and lines (e.g., datalines) 105. I/O circuit 117 can respond to signals CSEL0 through CSELnto select the signals on lines 175 that can represent the informationread from or programmed into memory cells 102. Column decoder 109 canselectively activate the CSEL0 through CSELn signals based on the A0through AX address signals on lines 103. I/O circuit 117 can select thesignals on lines 175 to exchange information between memory array 101and lines 105 during read and programming operations.

Signals DQ0 through DQN on lines 105 can represent information to beread from or written into memory cells 102. Lines 105 can include nodeswithin memory device 100 or pins (or solder balls) on a package wherememory device 100 can reside. Other devices external to memory device100 (e.g., a memory controller or a processor) can communicate withmemory device 100 through lines 103, 104, and 105.

Each of memory cells 102 can be programmed (e.g., programmed to have acertain state) to store information representing a value of a fractionof a bit, a value of a single bit, or a value of multiple bits such astwo, three, four, or another number of bits. For example, each of memorycells 102 can be programmed to store information representing a binaryvalue “0” or “1” of a single bit. The single bit per cell is sometimescalled a single level cell. In another example, each of memory cells 102can be programmed to store information representing a value for multiplebits, such as one of four possible values “00”, “01”, “10”, and “11” oftwo bits, one of eight possible values “000”, “001”, “010”, “011”,“100”, “101”, “110”, and “111” of three bits, or one of other values ofanother number of multiple bits. A cell that has the ability to storemultiple bits is sometimes called a multi-level cell (or multi-statecell).

Memory device 100 can receive a supply voltage, including supplyvoltages Vcc and Vss, on lines 106 and 107, respectively. Supply voltageVss can operate at a ground potential (e.g., having a value ofapproximately zero volts). Supply voltage Vcc can include an externalvoltage supplied to memory device 100 from an external power source suchas a battery or an alternating-current to direct-current (AC-DC)converter circuitry.

Memory device 100 can include a non-volatile memory device, and memorycells 102 can include non-volatile memory cells, such that memory cells102 can retain information stored thereon when power (e.g., Vcc, Vss, orboth) is disconnected from memory device 100. For example, memory device100 can be a flash memory device, such as a NAND flash or a NOR flashmemory device, or another kind of memory device, such as a variableresistance memory device (e.g., a phase change or resistive randomaccess memory (RAM) device).

Memory device 100 can include a memory device where memory cells 102 canbe physically located in multiple levels on the same device, such thatsome of memory cells 102 can be stacked over some other memory cells 102in multiple levels over a substrate (e.g., a semiconductor substrate) ofmemory device 100.

One of ordinary skill in the art may recognize that memory device 100may include other elements, several of which are not shown in FIG. 1 soas not to obscure the embodiments described herein.

Memory device 100 may include memory devices and operate using memoryoperations (e.g., read, programming, and erase operations) similar to oridentical to memory devices and operations described below withreference to FIG. 2A through FIG. 6B.

FIG. 2A shows a schematic diagram of a portion of a memory device 200having a set of lines 270 _(A), 271 _(A), 272 _(A), and 273 _(A) and aset of lines 270 _(B), 271 _(B), 272 _(B), and 273 _(B), according to anembodiment of the invention. Lines 270, 271, 272, and 273 can bestructured as a set of conductive lines. Lines 270 _(B), 271 _(B), 272_(B), and 273 _(B) can be structured as another set of conductive lines.

At least a portion of lines 270 _(A), 271 _(A), 272 _(A), and 273 _(A)(e.g., lines 270 _(A) and 272 _(A)) can be configured as a set of datalines (e.g., top data lines). At least a portion of lines 270 _(B), 271_(B), 272 _(B), and 273 _(B) (e.g., lines 271 _(B) and 273 _(B)) can beconfigured as another set of data lines (e.g., bottom data lines). Lines270 _(A), 272 _(A), 271 _(B), and 273 _(B) can carry signals BL0, BL2,BL1, and BL3, respectively.

Memory device 200 can include lines (e.g., access line) 250 ₀, 251 ₀,252 ₀, and 253 ₀ that can carry corresponding signals WL0 ₀, WL1 ₀, WL2₀, and WL3 ₀. Lines (e.g., access lines) 250 ₁, 251 ₁, 252 ₁, and 253 ₁can carry corresponding signals WL0 ₁, WL1 ₁, WL2 ₁, and WL3 ₁. Lines(e.g., access lines) 250 ₀, 251 ₀, 252 ₀, and 253 ₀ can carrycorresponding signals WL0 ₂, WL1 ₂, WL2 ₂, and WL3 ₀. Lines (e.g.,access lines) 250 ₂, 251 ₂, 252 ₂, and 253 ₂ that can carrycorresponding signals WL0 ₁, WL1 ₁, WL2 ₁, and WL3 ₁.

FIG. 2A shows a particular number of access lines and data lines as anexample. However, the number of these lines can vary.

Memory device 200 can include sense circuits 240, 241, 242, and 243, andtransistors 220 _(A), 221 _(A), 222 _(A), 223 _(A) 220 _(B), 221 _(B),222 _(B), and 223 _(B). These transistors can form part of a selectcircuit, such as select circuit 120 of FIG. 1.

In a memory operation (e.g., a read operation), transistors 220 _(A) and222 _(A) can respond to a signal BLS_(A) to couple lines 270 _(A) and272 _(A) to sense circuits 240 and 242, respectively. Transistors 221_(B) and 223 _(B) can respond to a signal BLS_(B) to couple lines 271_(B) and 273 _(B) to sense circuits 241 and 243, respectively. SignalsBLS_(A) and BLS_(B) can have the same value during a memory operation.Thus, signal BLS_(A) and BLS_(B) can be the same signal.

Transistors 221 _(A) and 223 _(A) can respond to a signal GBL_(A) tocouple lines 271 _(A) and 273 _(A) to a node 299 (e.g., a common node).Node 299 can be coupled to a ground potential. Transistors 220 _(B) and222 _(B) can respond to a signal GBL_(B) to couple lines 270 _(B) and272 _(B) to node 299. Signal GBL_(A) and GBL_(B) can have the same valueduring a memory operation. Thus, signal GBL_(A) and GBL_(B) can be thesame signal.

Memory device 200 can include memory cells 210, 211, 212, and 213, andtransistors (e.g., select transistors) 261, 262, 263, 265, 266, and 267.Memory cells 210, 211, 212, and 213 can be arranged in memory cellstrings, such as memory cell strings 230, 231, 232, 233, 234, and 235.For simplicity, only six (230, 231, 232, 233, 234, and 235) of the 12memory cell strings in FIG. 2A are labeled.

Each memory cell string in memory device 200 can be coupled to twoassociated transistors among transistors 261, 262, 263, 265, 266, and267. For example, memory cell string 230 can be coupled to transistor263 (directly over string 230) and transistor 267 (directly under string230). FIG. 2A shows a memory cell string (e.g., 230, 231, 232, 233, 234,or 235) including only memory cells (e.g., 210, 211, 212, and 213) as anexample. However, a memory cell string may not necessary include onlymemory cells. A memory cell string can include, in addition to memorycells, transistors (select transistors) coupled to the memory cells suchas a transistor directly over the memory cells in the memory cell stringand a transistor directly underneath the memory cells in the memory cellstring. For example, in FIG. 2A, memory cell string 230 can includememory cells 210, 211, 212, and 213 and transistor 263 (directly overstring 230) and transistor 267 (directly under string 230).

FIG. 2A shows an example of 12 memory cell strings and four memory cells210, 211, 212, and 213 in each memory cell string. The number of suchmemory cell strings and the number of memory cells in each memory cellstring can vary.

As shown in FIG. 2A, memory device 200 can include lines 281, 282, and283 coupled to gates of transistors 261, 262, and 263, respectively.Lines 281, 282, and 283 can form part of select lines of memory device200 and can carry signals SG0 _(A), SG1 _(A), and SG2 _(A) (e.g., topselect gate signals), respectively. Memory device 200 can include lines285, 286, and 287 coupled to gates of transistors 265, 266, and 267,respectively. Lines 285, 286, and 287 can form part of select lines ofmemory device 200 and can carry signals SG0 _(B), SG1 _(B), and SG2 _(B)(e.g., bottom select gate signals), respectively.

Transistors 261, 262, and 263 can be controlled (e.g., turned on orturned off) by signals SG0 _(A), SG1 _(A), and SG2 _(A), respectively.Transistors 265, 266, and 267 can be controlled (e.g., turned on orturned off) by signals SG0 _(B), SG1 _(B), and SG2 _(B), respectively.Signal SG0 _(A) and SGO_(B) can have the same value during a memoryoperation. Thus, signal SG0 _(A) and SG0 _(B) can be the same signal.Signal SG1 _(A) and SG1 _(B) can have the same value during a memoryoperation. Thus, signal SG1 _(A) and SG1 _(B) can be the same signal.Signal SG2 _(A) and SG2 _(B) can have the same value during a memoryoperation. Thus, signal SG2 _(A) and SG2 _(B) can be the same signal.

In a memory operation (e.g., a read operation), sense circuits 240, 241,242, and 243 can generate signals SDout0, SDout1, SDout2, and SDout3,respectively. The levels of signals SDout0, SDout1, SDout2, and SDout3can be based on the levels of signals BL0, BL1, BL2, and BL3,respectively. The levels of signal SDout0, SDout1, SDout2, and SDout3can be used to determine the states (e.g., values) of information storedin memory cells 210, 211, 212, and 213 of a selected memory cell set, asdescribed in more detail below.

FIG. 2B repeats specific portions of the memory device of FIG. 2A,including memory cell sets formed by memory cells 210, 211, 212, and 213of memory cell strings 230, 231, 232, and 233. As shown in FIG. 2B,memory cells 210, 211, 212, and 213 can be arranged in memory cell setsin rows, such that each of the memory cell sets can be included in adifferent row. For example, in FIG. 2B, memory cells 210 can be arrangedin a memory cell set 210 ₂ in row 290. Memory cells 211 can be arrangedin a memory cell set 211 ₂ in row 291. Memory cells 212 can be arrangedin a memory cell set 212 ₂ in row 292. Memory cells 213 can be arrangedin a memory cell set 213 ₂ in row 293. FIG. 2B shows an example of fourmemory cell sets in four respective rows; the number of memory cell setsand the number of corresponding rows can vary.

Memory cells of a memory cell set in a row can share (e.g., be directlycoupled to) the same access line. For example, memory cells 210 ofmemory cell set 210 ₂ can share the same line 250 ₂. Memory cells 211 ofmemory cell set 211 ₂ can share the same line 251 ₂. Memory cells 212 ofmemory cell set 212 ₂ can share the same line 252 ₂. Memory cells 213 ofmemory cell set 213 ₂ can share the same line 253 ₂.

Each of the memory cell sets can include four memory cells from fourdifferent memory cell strings. For example, memory cell set 211 ₂ caninclude four memory cells 210 from four different memory cell strings230, 231, 232, and 233. In another example, memory cell set 211 ₂ caninclude four memory cells 211 from four different memory cell strings230, 231, 232, and 233. FIG. 2B shows an example of four memory cells ineach memory cell set; the number of memory cells in each memory cell setcan vary.

Memory cells in other memory cell strings (e.g., 234, 235, and othermemory cell strings in FIG. 2A) of memory device 200 can also bearranged in memory cell sets in different rows similar to those of thememory cells of memory cell strings 230, 231, 232, and 233 of FIG. 2B.

In a memory operation (e.g., read or write operation), memory device 200can select memory cell strings to access a memory cell set of theselected memory cell strings. For example, memory device 200 can selectmemory cell strings 230, 231, 232, and 233 to access a memory cell set210 ₂, 211 ₂, 212 ₂, or 213 ₂. The memory cell sets in memory device 200(FIG. 2A and FIG. 2B) can be selected one memory cell set at a time. Aselected memory cell set refers to the memory cell set that is selectedto be accessed in a memory operation, so that memory device 200 can(e.g., in a write operation) store information in memory cells in theselected memory cell set or obtain (e.g., in a read operation) storedinformation from memory cells in the selected memory cell set.

In FIG. 2A, memory device 200 can selectively turn on transistors 261,262, 263, 265, 266, and 267 in a memory operation (e.g., a read or writeoperation). This enables a selected memory cell set included in theselected memory cell strings to be coupled to respective lines amonglines 270 _(A), 271 _(A), 272 _(A), and 273 _(A) and lines 270 _(B), 271_(B), 272 _(B), and 273 _(B).

In a memory operation, memory device 200 can turn on transistors (amongtransistors 261, 262, 263, 265, 266, and 267) that are associated withselected memory cell strings. For example, if memory cell set 211 ₂(FIG. 2B) is a selected memory cell set, memory device 200 can turn ontransistors 263 and 267 by, for example, providing appropriate voltagesto signals SG2 _(A) and SG2 _(B), respectively

In a memory operation, memory device 200 can turn off transistors (amongtransistors 261, 262, 263, 265, 266, and 267) that are associated withunselected memory cell strings. Unselected memory cell strings refer tothe memory cell strings that have no memory cells included in theselected memory cell set. For example, in FIG. 2B, if memory cell set211 ₂ is the selected memory cell set, memory device 200 (FIG. 2A) canturn off transistors 261, 262, 265, and 266 by, for example, providingappropriate voltages to signals SGO_(A), SG2 _(A), SG1 _(B), and SG3_(B), respectively.

In a write operation, memory device 200 can concurrently storeinformation in memory cells of a selected memory cell set. For example,if memory cell set 211 ₂ in FIG. 2B is selected, then memory device 200can concurrently store information in four memory cells 211 of memorycell set 211 ₂. In this example, memory device 200 can store informationin two memory cells 211 (in memory cell strings 230 and 232) based onvalues of signals on lines 270 _(A) and 272 _(A) (e.g., signals BL0 andBL2), respectively. Memory device 200 can store information in the othertwo memory cells 211 (in memory cell strings 230 and 232) based onvalues of signals on lines 271 _(B) and 273 _(B) (e.g., signals BL1 andBL3).

In a read operation, memory device 200 can concurrently obtaininformation from memory cells of a selected memory cell set. Forexample, in FIG. 2B, if memory cell set 211 ₂ is selected, then memorydevice 200 can concurrently obtain information in memory cells 211 ofmemory cell set 211 ₂. In this example, memory device 200 can obtaininformation from two memory cells 211 (in memory cell strings 230 and232) based on values of signals on lines 270 _(A) and 272 _(A) (e.g.,signals BL0 and BL2), respectively. Memory device 200 can obtaininformation in the other two memory cells 211 (in memory cell strings230 and 232) based on values of signals on lines 271 _(B) and 273 _(B)(e.g., signals BL1 and BL3).

Thus, as described above, memory device 200 can perform an operation ona portion (e.g., one half) of the memory cells of a selected memory cellset through lines 270 _(A) and 272 _(A) (e.g., top data lines) and onanother portion (the other half) of the memory cells of the selectedmemory cell set through lines 271 _(B) and 273 _(B) (e.g., bottom datalines). The operation can include a read or write operation.

FIG. 3 shows a schematic diagram of a portion of memory device 200including sense circuit 240, according to an embodiment of theinvention. As shown in FIG. 3, sense circuit 240 can include transistors328 and 329 and a sense stage 325. Transistor 328 can be located betweena supply node 306 and a node 370. Supply node 306 can be provided with avoltage (e.g., supply voltage) Vcc. Transistors 328 and 329 can becontrolled by signals PreCh and Vclamp, respectively. Sense stage 325can generate signals SDout0 based on signal SDin0. Transistors 328 and329 are shown as part of sense circuit 340 as an example. Transistor 328or 329, or both, can be separated from sense circuit 340. For example,transistor 328 can be part of a precharge circuit (not shown) andtransistor 329 can be part of another circuit (e.g., a clamp circuit,not shown) of memory device 200.

FIG. 4 is a timing diagram for the signals of FIG. 3 during an exampleread operation of memory device 200 (FIG. 2A and FIG. 2B), according toan embodiment of the invention. In the read operation associated withFIG. 4, as described below, memory cell set 211 ₂ in row 291 (FIG. 2B)is assumed to be a selected memory cell set. Thus, in FIG. 2B, line 251₂ can be a selected access line. Lines 250 ₂, 252 ₂, and 253 ₂ can beunselected access lines. During the example read operation, each ofsignals BL0, BL1, BL2, and BL3 (FIG. 2A) can indicate the state of arespective memory cell 211 of memory cell set 211 ₂.

In FIG. 4, times T0 through T4 represent different times during a readoperation. Voltages V0 through V8 represent different voltages that canbe provided to the signals of FIG. 4. The values (e.g., 0.5V, 1V, 1.2V,1.5V, and 5V) associated with the voltages in FIG. 4 are example values.Other values can be used. The waveforms in FIG. 4 are not scaled.

At time T0 during the read operation, signal BLS_(A) can change fromvoltage V0 to voltage V8 to couple line 270 _(A) (FIG. 3) to sensecircuit 240. Signal PreCh can change from voltage V5 to voltage V0 tocouple node 370 to supply node 306. Signal Vclamp can change fromvoltage V0 to voltage V4 to couple line 270 _(A) to node 370. With thiscondition, signal BL0 can change from voltage V0 to voltage V1,indicating that line 270 _(A) is charged (e.g., precharged) to voltageV1. Signal SDin0 can change from level 400 to level 401. Each of levels400 and 401 can correspond to a certain voltage.

At time T1, signal Vclamp can change from voltage V4 to voltage V0 todecouple line 270 _(A) from node 370. This may put line 270 _(A) in afloating state (e.g., electrically unconnected to node 370 and sensestage 325).

At time T2, signals SG2 _(A) and SG2 _(B) (FIG. 2B) can change fromvoltage V0 to voltage V7. Signal WL0 ₂, WL2 ₂, and WL3 ₂ (associatedwith unselected access lines in this example) can change from voltage V0to voltage V6. Signal WL1 ₂ (associated with the unselected access linein this example) can change from voltage V0 to voltage V2. The timeinterval from time T0 to time T2 can be a precharge time interval whereline 270 _(A) can be charged to voltage V1. Time T1 can be the beginningof the precharge time interval. Time T2 can be the end of the prechargetime interval. Thus, at time T2 in FIG. 4, signal PreCh can change fromvoltage V0 to voltage V5 to decouple node 370 from supply node 306.

From time T2 and after, signal BL0 can have either voltage V0 or voltageV1, depending on the state of memory cell 211 (a selected memory cell)of memory cell string 230 (FIG. 2B). For example, if memory cell 211 ofmemory cell string 230 has one state, then signal BL0 can remain atvoltage V1. If memory cell 211 of memory cell string 230 has anotherstate, then signal BL0 can change (e.g., discharge) from voltage V1 tovoltage V0. The state of a memory cell (e.g., memory cell 211 of memorycell string 230, in this example) corresponds to a value of informationstored that memory cell.

The time interval from time T3 to time T4 can be a sense time intervalwhere sense stage 325 can operate to sense the level (e.g., voltage) ofBL0 (e.g., by way of signal SDin0). Thus, at time T3 in FIG. 4, signalVclamp can change from voltage V0 to voltage V5 to couple line 270 _(A)to node 370. At time T3, signal Vclamp can change from V0 to voltage V3.From time T3 and after, signal SDin0 can have either a level 400 or alevel 401, depending on the voltage of signal BL0. For example, ifsignal BL0 has voltage V1, then signal SDin0 can remain at level 401. Ifsignal BL0 has voltage V0, then signal SDin0 can change from level 401to level 400.

At time T4, signals SG2 _(A), SG2 _(B), WL0 ₂, WL1 ₂, WL2 ₂, WL3 ₂,BLS_(A), and Vclamp can change from their respective voltage to voltageV0. Signal SDout0 can have either a level 411 or a level 412, dependingon state of memory cell 211 of memory cell string 230 (FIG. 2B). Forexample, signal SDout0 can have level 411 if memory cell 211 of memorycell string 230 has one state. Signal SDout0 can have level 412 ifmemory cell 211 of memory cell string 230 has another state. Each oflevels 411 and 412 can correspond to a certain voltage.

Other sense circuits 241, 242, and 243 (FIG. 2A) of memory device 200can include features similar to or identical to those of sense circuit240 of FIG. 3. Thus, in a read operation of memory device 200, asdescribed above with reference to FIG. 3 and FIG. 4, sense circuits 241,242, and 243 and their associated signals can have waveforms similar tothose shown in FIG. 4.

Memory device 200 (FIG. 2A) may have an improved (e.g., increased) datathroughput. For example, in comparison with some conventional memorydevices (e.g., devices with shielded data line architecture), the numberof memory cells of memory device 200 that memory device 200 canconcurrently access (e.g., in a read or operation) can be twice thenumber of memory cells that the conventional memory devices can access.The improved data throughput of memory device 200 can be attributed tothe arrangement of data lines (e.g., top and bottom data lines, asdescribed above with reference to FIG. 2A to FIG. 4).

Memory device 200 may also have an improved (e.g., lower) powerconsumption. For example, in comparison with some memory devices, memorydevice 200 may use only a portion (e.g., from time T3 to time T4 in FIG.4) of a read operation to sense signals (e.g., BL0, BL1, B12, and BL3)on the data lines in order to determine the state of selected memorycells. Some conventional memory devices may use a relatively greatertime interval for similar sensing. Since memory device 200 uses asmaller time interval for sensing during a read operation, its powerconsumption during a read operation may be lower than that of someconventional memory devices.

FIG. 5A shows a side view of a portion of a structure of memory device200 of FIG. 2A, according to an embodiment of the invention. FIG. 5Bshows a top view of the structure of memory device 200 of FIG. 5A. FIG.5C shows another side view of the structure of memory device 200 of FIG.2A.

As shown in FIG. 5A, memory device 200 can include a substrate 515,which can be formed from a semiconductor material, such as silicon.Memory device 200 can include different levels 501 through 508 overlyingsubstrate 515 in a Z-direction, which is substantially perpendicular(e.g., perpendicular) to an X-direction and a Y-direction (FIG. 5C).

In FIG. 5A, lines 270 _(B), 271 _(B), 272 _(B), and 273 _(B) can belocated on level 501. Lines 270 _(A), 271 _(A), 272 _(A), and 273 _(A)can be located on level 508. Memory cells 210, 211, 212, and 213 can belocated on levels 503, 504, 505, and 506, respectively. Lines 270 _(A),271 _(A), 272 _(A), and 273 _(A) can be separate layers of conductivematerials overlying memory cells 210, 211, 212 and 213 and substrate515. Lines 270 _(B), 271 _(B), 272 _(B), and 273 _(B) can be separatelayers of conductive material located in (e.g., formed in or formed on)substrate 515. FIG. 5B shows an example where lines 270 _(B), 271 _(B),272 _(B), and 273 _(B) can be separate doped regions (e.g., conductivep-type or n-type doped regions) formed in substrate 515. However, lines270 _(B), 271 _(B), 272 _(B), and 273 _(B) can be separate layers ofconductive material formed over substrate 515.

Each of memory cell strings (e.g., 230, 231, 232, and 233) can belocated between a respective line among lines 270 _(A), 271 _(A), 272_(A), and 273 _(A) and a respective line among lines 270 _(B), 271 _(B),272 _(B), and 273 _(B). Lines 283 and 287 can be located on levels 507and 502, respectively.

As shown in FIG. 5A and FIG. 5C, transistors 261, 262, and 263 (FIG. 2A)can be located on level 507 and surrounded by corresponding lines 281,282, and 283. Transistors 265, 266, and 267 (FIG. 2A) can be located onlevel 502 (FIG. 5C) and surrounded by corresponding lines 285, 286, and287. Each of memory cell strings (e.g., 230, 231, 232, 233, 234, and235) of memory device 200 can include a body region 561 having a lengthin the Z-direction. Access lines of memory device 200 can be locatedalong the length of body regions of respective memory cell strings. Forexample, lines (e.g., access lines) 250 ₂, 251 ₂, 252 ₂, and 253 ₂ canbe located along the length of respective body regions 561 of memorycell strings 230, 231, 232, and 233.

As shown in FIG. 5A, FIG. 5B, and FIG. 5C, memory device 200 can includecontacts, such as 530, 531, 532, 533, 544, and 535, coupled betweenrespective memory cell strings (e.g., 230, 231, 232, 233, 234, and 235)and lines 270 _(A), 271 _(A), 272 _(A), and 273 _(A). Each of memorycell strings (e.g., 230 through 235) can also include a material 562between body region 561 and corresponding access lines. For example, asshown in FIG. 5A, memory cell strings 230, 231, 232, and 233 can includematerial 562 between region 561 and lines 250 ₂, 251 ₂, 252 ₂, and 253₂. Material 562 can substantially surround body region 561. Each ofaccess lines (e.g., 250 ₂, 251 ₂, 252 ₂, and 253 ₂ in FIG. 5A) cansubstantially surround a cross section of body region 561 of arespective memory cell string (e.g., 230, 231, 232, and 233). The crosssection of body region 561 can have a circular shape. Body region 561can include semiconductor material, such as silicon (e.g., dopedpolysilicon of p-type or n-type).

Material 562 can include a material (or materials) that can beconfigured to store information in memory cells 210, 211, 212, and 213.For example, material 562 can include charge storage material, such as acombination of a tunnel dielectric layer, a silicon oxide layer, and acharge blocking layer, or a combination of a silicon nitride layer, apolysilicon layer, and a nitride layer, or other materials that canprovide a charge storage function to represent a value of informationstored in the memory cells of memory cells 210, 211, 212, and 213. As anexample, material 562 can include a combination of a tunnel dielectricdirectly contacting the body region 561, a charge storage material(e.g., polysilicon floating gate) directly contacting the tunneldielectric, and a charge blocking material directly contacting thecharge storage material.

FIG. 5B also shows the location of memory cell set 213 ₂ that includesmemory cells 213 arranged in row 293. As described above with referenceto FIG. 2A and FIG. 2B, when a memory cell set is selected, informationcan be stored in (e.g., in a write operation) or obtained from (in aread operation) a portion of the memory cell set through different setsof data lines (e.g., top and bottom data lines). For example, in FIG.5B, when memory cell set 213 ₂ is selected, information can be stored inor obtained from two memory cells 213 of memory cell set 213 ₂ throughlines 270 _(A) and 272 _(A) (e.g., top data lines) and the other twomemory cells 213 of memory cell set 213 ₂ through lines 271 _(B) and 273_(B) (e.g., bottom data lines).

FIG. 6A shows a side view of a portion of a structure of a memory device600 having lines 270 _(B), 271 _(B), 272 _(B), and 273 _(B) (e.g.,including bottom data lines 271 _(B) and 273 _(B)) formed over substrate515, according to an embodiment of the invention. FIG. 6B shows anotherside view of a portion of the structure of memory device 600 of FIG. 6A,according to an embodiment of the invention.

Memory device 600 can be a variation of memory device 200 describedabove with reference to FIG. 2A through FIG. 5C. Thus, memory device 600can include elements similar to or identical to those of memory device200. For simplicity, the description of similar or identical elementsbetween memory devices 200 and 600 is not repeated in the description ofFIG. 6A and FIG. 6B.

As shown in FIG. 6A and FIG. 6B, lines 270 _(B), 271 _(B), 272 _(B), and273 _(B) can be formed as separate layers of conductive material oversubstrate 515. Substrate 515 can include a portion 640 underneath lines270 _(B), 271 _(B), 272 _(B), and 273 _(B). In portion 640, elementssuch as transistors for sense circuits of memory device 600 (e.g.,similar to sense circuit 140 in FIG. 1, or sense circuits 240, 241, 242,and 243 in FIG. 2A) or for other elements of memory device 600 can beformed.

The illustrations of the apparatus (e.g., memory device 200) areintended to provide a general understanding of the structure of variousembodiments and are not intended to provide a complete description ofall the elements and features of an apparatus that might make use of thestructures described herein.

The apparatuses (e.g., memory device 200 or part of memory device 200,including memory control unit 118 of FIG. 1 and sense circuit 240 ofFIG. 2A and FIG. 3) described above may all be characterized as“modules” (or “module”) herein. Such modules may include hardwarecircuitry, single and/or multi-processor circuits, memory circuits,software program modules and objects and/or firmware, and combinationsthereof, as desired and/or as appropriate for particular implementationsof various embodiments.

Memory device 200 may be included in apparatuses (e.g., electroniccircuitry) such as high-speed computers, communication and signalprocessing circuitry, single or multi-processor modules, single ormultiple embedded processors, multi-core processors, message informationswitches, and application-specific modules including multilayer,multi-chip modules. Such apparatuses may further be included assub-components within a variety of other apparatuses (e.g., electronicsystems), such as televisions, cellular telephones, personal computers(e.g., laptop computers, desktop computers, handheld computers, tabletcomputers, etc.), workstations, radios, video players, audio players(e.g., MP3 (Motion Picture Experts Group, Audio Layer 3) players),vehicles, medical devices (e.g., heart monitor, blood pressure monitor,etc.), set top boxes, and others.

The embodiments described above with reference to FIG. 1 through FIG. 6Binclude apparatuses and methods having a first set of conductive lines,a second set of conductive lines, and memory cells located in differentlevels of the apparatus and arranged in memory cell strings. At least aportion of the first set of conductive lines is configured as a firstset of data lines. At least a portion of the second set of conductivelines is configured as a second set of data lines. Each of the memorystrings is coupled to a respective conductive line in the first set ofconductive lines and a respective conductive line in the second set ofconductive lines. Other embodiments including additional apparatuses andmethods are described.

The above description and the drawings illustrate some embodiments ofthe invention to enable those skilled in the art to practice theembodiments of the invention. Other embodiments may incorporatestructural, logical, electrical, process, and other changes. Examplesmerely typify possible variations. Portions and features of someembodiments may be included in, or substituted for, those of others.Many other embodiments will be apparent to those of skill in the artupon reading and understanding the above description.

What is claimed is:
 1. An apparatus comprising: a first set ofconductive lines located on a first level of the apparatus, at least aportion of the first set of conductive lines configured as a first setof data lines; a second set of conductive lines located on a secondlevel of the apparatus, at least a portion of the second set ofconductive lines configured as a second set of data lines; and memorycells located in different levels of the apparatus and arranged inmemory cell strings, each of the memory strings coupled to a respectiveconductive line in the first set of conductive lines and a respectiveconductive line in the second set of conductive lines.
 2. The apparatusof claim 1, wherein the first set of conductive lines includes a firstconductive line, a second conductive line, a third conductive line, anda fourth conductive line, the second conductive line arranged betweenthe first and third conductive lines, the third conductive line arrangedbetween the second and fourth conductive lines, wherein the first andthird conductive lines are included in the first set of data lines, andthe second and fourth conductive line are excluded from the first set ofdata lines.
 3. The apparatus of claim 2, wherein the second set ofconductive lines includes a fifth conductive line, a sixth conductiveline, a seventh conductive line, and an eighth conductive line, thesixth conductive line arranged between the fifth and seven conductivelines, the seven conductive line arranged between the sixth and eighthconductive lines, wherein the sixth and eighth conductive lines areincluded in the second set of data lines, and the fifth and sevenconductive lines are excluded from the second set of data lines.
 4. Theapparatus of claim 3, wherein the memory cell string includes a firstmemory cell string coupled to the first and fifth conductive lines, anda second memory cell string coupled to the second and sixth conductivelines.
 5. The apparatus of claim 1, further comprising sense circuits,each of the sense circuits coupled to a respective data line in thefirst and second set of data lines, wherein a quantity of the sensecircuits is equal to a quantity of the data lines in the first andsecond set of data lines.
 6. The apparatus of claim 1, further includinga substrate, wherein one of the first and second sets of data lines islocated between the substrate and the memory cells.
 7. The apparatus ofclaim 1, wherein the apparatus comprises a memory device.
 8. Theapparatus of claim 1, wherein the apparatus comprises a system includinga memory device that includes the conductive lines and the memory cells.9. A method comprising: applying a signal to memory cells arranged in arow in a device obtaining information from a first portion of the memorycells through a first set of data lines located in a first level of thedevice; and obtaining information from a second portion of the memorycells through a second set of data lines located in a second level ofthe device.
 10. The method of claim 9, further comprising: coupling adata line in the first set of data line to a node; and coupling the nodeto a supply node; and decoupling the data line from the node.
 11. Themethod of claim 10, further comprising: decoupling the data line fromthe supply node; and coupling the data line to the node.
 12. The methodof claim 11, further comprising: generating a signal to indicate a stateof a memory cell coupled to the data line.